It's not really a superpower, the Flash just runs that fast because he is on a caffeine high. DC Comics has opposed the FLASH trademark of Flash Energy Company claiming that consumers are bound to be confused and think the energy drink is affiliated with DC Comics when it is not.
The Flash character was first introduced in 1940, a year before the bombing of Pearl Harbor, and the character is as big as ever. DC Comics owns several trademark registrations for THE FLASH and even owns a trademark registration for the look of the character. Another well known logo associated with the character is the lightening bolt in a circle that appears on the Flash's chest. However, DC Comics does not have a trademark registration for this logo and even refrains from calling it a trademark in its opposition to this mark.
In August 2016, the Flash Energy Company filed an intent to use trademark registration application for mark that can be seen above using the FLASH name and lightening bolt. Since the time of the filing of the mark, the company has since began to distribute the energy drink. DC Comics claims that based on the similarity of the marks and goods and services, consumers are likely to be deceived into falsely believing that the energy drink offered originates from or is otherwise associated DC Comics, or that there is some relationship between the energy drink and DC Comics.
I think DC Comics has an open and shut case here. The average customer when seeing the name and lightening bolt logo would most likely think this is associated with the Flash character and DC Comics. That is the definition of consumer confusing. Drink Flash while you can cause much like the superhero, I expect it to disappear soon.